Sintered hard metal alloys



Patented Aug. 23, 1938 PATENT OFFICE 2,128,146 SINTERED HARD IVIETAL ALLOYS Josef Hinniiber,

assignor to General Electric Company,

nectady, N. Y.

Essen-Ruttenscheid, Germany,

Sche- No Drawing. Application July 7, 1936, Serial No. 89,469. In Germany 3 Claims.

The invention relates to sintered hard metal alloys intended for the chip-removing machining of steel and steel alloys, and has for its object sintered hard metal alloys which when used for the purpose set forth show an increased efficiency in comparison with the sintered hard metal alloys hitherto known.

As known, the sintered hard metal alloys used for the chip-removing treatment of steel and steel alloys contain tungsten carbide, auxiliary metals of lower melting point, such as cobalt or nickel, and titanium carbide or tantalum carbide. The good effect, as to the increase of emciency, of the addition of the two last-named carbides is based upon the notable resistance to the formation of craters. Such craterous cavities frequently occur with sintered hard metal alloys, which besides auxiliary metal contain no alloying element but tungsten carbide, immediately behind the cutting edge and cause a comparatively rapid destruction of the cutting edge. With coarse approximation one may say that with increasing addition of titanium carbide or tantalum carbide also the resistance increases to formation of craters, whilst, however, simultaneously the properties of strength of the alloy deteriorate, so that in general the addition of these carbides has to be kept within determined limits.

It has now appeared that the hard metal alloys under consideration containing titanium carbide or tantalum carbide and hitherto used for the chip-removing mechanical working of steels and steel alloys surprisingly are far surpassed as to their efliclency in this work by sintered hard metal alloys which besides tungsten carbide and auxiliary metal of lower melting point contain both titanium carbide and vanadium carbide, the content of titanium carbide exceeding that of vanadium carbide. The content of auxiliary metal, such as cobalt, nickel, iron, manganese, separate or mixed, or alloys of these metals for example with tungsten, molybdenum or chromium, may vary within the limits from 0.5 to 20%, while the content of titanium carbide may amount to from 3 to 30% and that of vanadium carbide to from 0.3 to The best results are August '7, 1935 (01. 75-136) obtained with from 3 to 10% auxiliary metal, from 5 to 20% titanium carbide and from 0.5 to 5% vanadium carbide. In the alloy the carbides occur at least partly as a heterogeneous mixture.

Alloys of the compositions hereinbefore given 5 are excellently suited for the various kinds of machining steel and steel alloys and their use is of particular advantage in executing smoothening work. So, for example, a sintered hard metal alloy composed of about 5.5% cobalt, 16% tita- 1o nium carbide, 1% vanadium carbide, balance tungsten carbide, showed in smoothening steel pieces of a strength of about 90 kg/mm a life up to re-grinding of up to twice as long as a corresponding alloy containing no vanadium carbide.

The word auxiliary metal when used in the following claims is to be understood as comprising cobalt, nickel, iron manganese, separate or mixed, or alloys of these metals with, for example, tungsten, molybdenum or chromium. 20

What I claim and Patent is:

l. A sintered alloy containing about 5.5% cobalt, about 16% titanium carbide, about 1% vanadium carbide, and the remainder tungsten carbide.

2. A sintered alloy containing about .5% to 20% of auxiliary metal, about 3% to titanium carbide, about .3% to 10% vanadium carbide with the remainder tungsten carbide, the. 30 titanium carbide and vanadium carbide being present in the alloy principally as a, heterogeneous mixture and the titanium carbide content of the alloy being greater than the vanadium carbide content.

3. A sintered alloy containing about .5% to ,20% of auxiliary metal, about 3% to 30% titanium carbide, about .3% to 10% vanadium carbide with the remainder tungsten carbide, the titanium carbide and vanadium carbide being present in the alloy at least partly as a heterogeneous mixture and the titanium carbide content of the alloy being greater than the vanadium carbide content.

desire to secure by Letters JOSEF HmNUBER. 

